1. Field of the Invention
The invention relates to a radio communicating apparatus having a function to detect a receiving state.
2. Related Background Art
In a radio communicating apparatus such as a business cordless telephone or the like, since channels other than the channel that is actually used are broken by noises which are generated from peripheral apparatuses, it is necessary to measure a radio wave environment in order to guarantee the stable operation. As a measurement of the radio environment performed there, it is a main way to measure an intensity of a radio wave of a radio channel by a radio wave measuring instrument and to judge the presence or absence of the radio wave.
In such a measuring instrument, since a threshold value for the judgment about the presence or absence of the radio wave, the sampling number per unit time, and the like cannot be set in detail, the judgment result is the absolute value.
FIG. 29 shows display contents in the case where the measurement was performed by a radio wave measuring instrument in the conventional apparatus.
Even if the radio wave environment of a location where the apparatus is installed is measured by the radio wave measuring instrument, there is actually a difference of radio wave characteristics between the measuring instrument and the apparatus. For example, as a factor of such a difference, there is a sensitivity or a matching performance of an antenna which is used, an influence by noises which the apparatus itself has, or the like. The true radio wave environment cannot be measured by the radio wave measuring instrument.
In the radio communicating apparatus such as a cordless telephone apparatus having a master and slaves for performing a radio communication with the master or the like, there is an apparatus such that the slave has a display for displaying an intensity of a radio wave that is received from the master during the speech communication.
Examples of a display of the intensity of the radio wave that is received from the master by the display of the slave will now be described with reference to FIGS. 30A to 30C. FIGS. 30A to 30C are diagrams showing display examples of the intensity of the radio wave that is received from the master by the display provided for the slave of the telephone apparatus.
As shown in FIGS. 30A to 30C, the display provided for the slave mentioned above is set so as to separately display the intensity of the radio wave that is received from the master by three stages. The intensity of the radio wave at each stage is shown by the number of marks “(” and it is shown that the radio wave becomes strong with an increase in number of marks. A black painted circle on a display screen indicates the master and a mark of the antenna shows the slave.
For example, when the slave receives the radio wave which is transmitted from the master and in which a degree of intensity is strong, as shown in FIG. 30A, two marks “(” are displayed on the display. When the slave receives the radio wave in which a degree of intensity is middle from the master, as shown in FIG. 30B, one mark “(” is displayed on the display. When the slave receives the radio wave in which a degree of intensity is weak from the master, as shown in FIG. 30C, the mark “(” is not displayed on the display.
However, by displaying the degree of intensity of the radio wave that is received from the master onto the display of the slave by the slave, although the degree of intensity of the radio wave that is received from the master can be informed to the user of the slave, a degree of intensity of the radio wave that is received by the master from the slave cannot be notified to the user of the slave. Therefore, there is a situation such that although the intensity of the radio wave that is transmitted from the master to the slave is enough, the user moves to a location where the intensity of radio wave from the slave to the master obstructs a speech communication without knowing such a fact. There is, consequently, a case where the speech communication from the slave to the master is interrupted due to the movement of the slave to such a position.